Sand casting



j/ llll Feb. 3, 1925 `,525,o2'7

' J. N. EARLY SAND CASTING Filed Jan. 10, 1924 A %(7 #wwi/ To all whom 'it may concem:

Patented Feb. 3, 1925.,

UNITED STATES 1,525 ,027 PATENT. OFFICE.

JOHN N. EARLY, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO W. J'i EARLY SONS FOUNDRY CORPORATIO'N, OF PITTSBURGH, PENNSYLVANIA, A GORPOEATION OF DELAWARE.

SAND CASTING'.

i Application filed January 10, 1924. Serial No( 685,425.

Be it known that I, JOHN N. EARLY, a citizen of the United States, and resident of Pittsburgh, in the county of Allegheny, State of Pennsylvania, have inv'ented certain new and useful Improvements in Sand Castings, of which the following is a specification. v

This invention relates to an alloy of iron, the main constituents of which are iron, silicon, sulfur, phosphorus, manganese, and carbon, with or without small quantities of nickel and chromium.

This alloy is characterized by having great strengthand a very hard chill surface; also by the fact that the chill depth may be readily controlled by the operator, either in a sand or chill mold.

Heret-cfare, in casting iron alloys the chill depth has been uncontrollable, except by the use ofchill pieces or chill molds, and even then has been more or less of an uncertain matter, while the present alloy permits of positive control of the chill depth at all times. v

Generically, the invention consists in castings containing the elements and the per-- centages thereof, following- Such castings show remarkable results in tensile strength and in wearing and abrasive qualities, and in the resistance to the action of heat. I

A specific analysis of one of the characteristic castngs made under my method and of my new alloy is silicon 121%, sulp fur 142%, phosphorus .57 manganese.

21%, free carbon 1.76%, and combined carbon 154%. I

I have discovered that the combined carbon varies more or less in proportion with the sulfur content of the alloy, although some of the other elements may also efl'ect 'the percentage of combined carbon to a negligible extent.

The most notable characteristic of this new alloy is its ability to chill in either a sand or chill mold, and the ease with which the operator can control the depth of' formed from my novel alloy and will come i out of the mold with a uniform depth of chill of such hardness that they will outwear ordinary cast rolls from four to five times.

The depth of chill on castings formed from my novel alloy is readily controlled when`they are cast in either sand or chill molds by varying the sulfur content and by varying the heat at which the metal is poured into the molds. I

Alloys having a high content of combined carbon have been made heretofore, but all of such alloys, such as 'the well known adamite, and similar alloys have depended .upon the high chromium content to cause It will also be noted that due to the'peculiar characteristics of adamite and similar high chromium alloys, they can not be produced commercially in a cupola, while the present alloy may readily be produced in a cupola, electric furnace, or other smelting furnace. In fact, for several months past the alloy of this invention has been commercially .produced in a cupola.

When it is desired to increase the tensile strength and toughness of the castings, I may add arelatively small' amount of chromium and v nickel, as for instance, chromium .15% to- .25% and nickel .05% to .25%. It will be noted, however, that when either chromium or nickel alone, or both together are added to my alloy, the ercentage of combined carbon remains substantially the same.

In producing my novel alloy, the following method is carried out-.

I first charge a cupola or other smelting -furnace with suitable scrap, pigs, 'or ores, 'of the' proper analysis to enable' me to secure the proper'pro-portion of silicon, sulfur, phosphor us, manganese, and carbon,

ing these ingredients are also added. After the mix is made up it is heated to from 2500 degrees to 2700 degrees Fahrenheit to melt the metals. That is, the mix is raised to a heat materially above the melting temperature so as to obtain a good pouring temperature. After the mix has been melted it is tapped and then poured in the molds at a temperature ot :from 2300 degrees to 2500 degrees Fahrenheit.

The depth of chill on the finished casting is controlled primarily by the pouring temperature. That is, the hotter the pouring temperature the deeper will be the chill; also the depth of chill can be controlled somewhat by the sulfur content of the i mix, that is, the greater the sulfur conwith definite depths o `entire surface.

tent the greater the. chill. However, the sulfur content is known and when' it is slightly higher or lower than necessary to produce the correct depth of chill, the pouring temperature may be increased or lowered accordingly to give the correct depth of chill.

For instance, if the sulfur content were such that it would tend to cause too great a depth of chill, then the pouring temperature would be lowered to lessen the chilling efi'ect of the casting heat, while if the sulfur content was slightly lower than necessary to give the desired depth of chill, 'the pouring heat would be increased.

This alloy is peculiar to itself in that it will form a uniform depth of chill over the entire surface of a casting in a sand mold, and the depth of such chill can be" varied or controlled by the pouring temperature, so that an operator may readily produce castings such as crusher rolls, dies, rolling mill rolls, rollin mill guides, etc., chill over their Experience has shown that crusher rolls, rolling mill guides, dies and other castings formed from my alloy will outlast as many as four or five similar articles made from ordinary cast iron alloys or steels. The chilled surfaces of articles made from my alloy are very hard and will outwear any commercial steel or iron alloy known at this time. lln fact, in most cases it is so hard that it will withstand any of the commercial forms of tool steel and cannot be turned on a lathe, but must be ground to finish.

Referring to the accompanying drawings, Figure 1 is a transverse elevation through a rolling mill roll.

Figure 2 is a transverse section through a rolling mill guide.

Figur-e 3 is a transverse 'section through a small round cast bar.

easner lteferring particularly to the drawings, the numeral 2 in each of the above figures designates the hard uniform chilled outer surface of the castings and the numeral 3 designates the soft' or unchilled center. All of the above articles can and are produced in the well known sand mold and their chill depth has been produced without the use of any form of chill pieces or mold.

The uniformity of the chill is due to the novel composition of my new alloy and the depth of the chill is controlled by the pouring temperature so that the operator after little experience may readily make chill depths of from one-eighth or less to one and one-half or more inches from the 'same alloy mix by. simply varying the pouring temperature.

Applicant believes he is the first to produce an iron alloy capable of being cast in sand and to produce a uniform depth of chill withoutthe use of chill molds or chill pieces, and therefore, does not wish to be limited to the exact articles shown and described, but intends his claims to be construed broadly so 'as to include any article cast in sand from his or the equivalent of his alloy, which is provided with a uniform depth of chill.

ll claim- 1. As an article of manufacture a sand casting having a uniform chill depth over its entire surface and an unchilled center.

2. As an article of manufacture a sand "casting having a uniform chill depth over its entire surface and an unchilled center, said chilled surface being characterized by being of such hardness that it can not be cut by the commercial forms of tool steel.

3. As an article of manufacture a sand cast roll for rolling mills and the like havinga uniform chill depth over its entire surface and an unchilled center.

4. As an article of manufacture a sand casting of iron alloy comprising essentially silicon .75% to 150%; sulfur .05% to 25%; phosphorus .25% to .75%; manganese .20% to .70%; combined carbon of from 100% to 200%; some free carbon; and iron approximately sufi'icent to complete the 100%, said casting being characterized by having a uniform chill depth over its 'entire surface and an unchilled center, the depth of said chill being under the control of the operator due to the peculiarcharacteristic o the alloy which permits the control of the chill by varying either the sulfur content or the pouring temperature, or both.

In testimony whereof, I have hereunto signed my name.

JOHN N. EARLY. 

